Stop motion mechanism for knitting machines



June 10, 1952 J. WACHSMAN STOP MOTION MECHANISM FOR KNITTING MACHINES Filed June 22, 1950 lllill, Fill/(Will 'IIIIA7IIIII IN VEN TOR. Jaafi Wars ma Patented June 10, 1952 STOP MOTION MECHANISM FOR KNITTING MACHINES Jacob Wachsman, Brooklyn, N. Y.

Application June 22, 1950, Serial No. 169,621

8 Claims.

1 The present invention relates to stop motion mechanisms, and, more particularly, relates to improved stop motion mechanisms for use in connection with knitting machines and the like,

which mechanisms are of the type responsive to the breakage of the yarn, thereby requiring a predetermined tension in the yarn at all times in order to prevent the stop mechanism from operating upon the appearance of slack in the yarn during normal operation of the machine.

Accordingly, an object of the present invention is to provide such stop motion mechanism having improved slack take-up means which are simple and economical in construction and reliable in operation.

Another object is to provide such stop motion mechanism particularly adapted for controlling an electrical circuit which effects stoppage of the machine.

Another object is to provide such stop motion mechanism wherein a single switch circuit is adapted to be controlled by a pair of yarn tension responsive members whereby the number of electrical circuits is greatly reduced in knitting machines wherein a multiplicity of strands of yarn control the stoppage of the machine.

A further object is to provide such stop motion mechanism wherein movement of a pair of yarn tension responsive members is resisted by springs which are adjustable by common means whereby adjustment of the stop motion mechanisms is simplified.

Other and further objects will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

In accordance with the invention, the foregoing objects and advantages are accomplished by providing a stop motion mechanism which generally comprises in combination a brace or bracket adapted for attachment to the knitting machine or the like, yarn guide means on the base, a member responsive to tension in the yarn adapted to effect operation of the stop motion mechanism upon breakage of the yarn, the memher being mounted on the base and having one end provided with yarn guide means, and a gravity responsive member pivotally mounted on the base having yarn guide means at its ends adjacent the guide means on the base and the first mentioned member respectively.

While the mechanism illustrated herein is adapted to control the stoppage of the machine by electrically, pneumatically, hydraulically, or mechanically operated devices, the mechanism as shown is particularly adapted for controlling an electrical circuit and, in accomplishing this, reduces the number of electrical circuits in mayarn breakage responsive devices by enabling a chines under the control of a multiplicity of pair of yarn tension responsive arms to control a single circuit.

In the embodiment illustrated herein and about to be described, the foregoing is facilitated by providing a switch on the base having a pair of contact elements electrically connected to one terminal of the switch and mounting a pair of yarn responsive members side by side on the base, each provided with a portion for engaging a contact element and each electrically connected to the other terminal of the switch, whereby breakage of the yarn detected by either of the responsive members effects closing of the stop motion circuit.

The construction of the mechanism is further simplified by providing a spring for each yarn responsive member which urges the contact portion towards the contact elements and by providing common means for simultaneously adjusting both springs.

A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawing, forming a part of the specification, wherein;

Fig. 1 is a top view of a device in accordance with the invention wherein a pair of yarn responsive members control a single switch circuit.

Fig. 2 is a side view of the device with a portion of the switch housing broken away and one of the yarn responsive members shown in a normal position during operation and the other yarn responsive member shown in circuit closing position as a result of breakage of the yarn.

Fig. 3 is a bottom view of the device shown in Figs. 1 and 2.

Fig. 4 is a staggered sectional view taken along the line 4-4 on Fig. 2.

Referring to the drawing in detail, there is shown a device generally comprising a base or bracket [0 including a switch housing II, a pair of yarn tension responsive arms l2 pivotally mounted on the base, and slack take-up means for each arm including a guide eye l4 fixed on the base and gravity operable means l5 cooperating with the eye M, as described hereinafter.

The arms l2 are mounted in side by side relation on the base with one'arm at one side of the switch housing II and the other arm at the other side thereof. To accomplish this, each arm is formed of relatively stiff wire and has shaft portions I6 and I! seated in a recess formed in the side walls of the switch housing at the edge which the bracket overlies and held in the assembled relation by securing the switch housing :to the-bracket at l8'and l9.

Each-arm I2 has a U-shaped switch engaging portion 20 between its shaft portions extending to the left of the pivot, as viewed in Fig. 4, one of the legs of this portion having a loop 2| formed therein; and each arm has a short portion 22 perpendicular to the shaft portion H disposed adjacent a side wall of the switch housing, a'por tion 24 extending outwardly from the. side wall, an elongated lengthwise extending portion 25 which is slightly bendable and resilient, and an inwardly extending transverse portion 25 at the iree' endiof thezarm supporting a yarn guide eye "21.

lnsshownlin Figsi 2 and-e, the switch housing i l. hasa switch member 29 mounted therein and electrically insulated therefrom in any suitable -manner. .tMemberT'ES constitutes one terminal of 71118 switch'means'andis provided with a pair of electrically connected "contact elements 39 each adaptedtobe engaged by the U-shaped portions 28 of the arms 12. The housing constitutes the other terminal of the switch means and the arms iZ-arezin electrical connection therewith, where- "by arcircuit is adapted tohe established for efiect= ingstoppage of the machine when either of the .arms en agesone 'of.,the contact elements 39.

The arms I3 are each urged about their pivots :to cause the ,U-portionsEt to engage the con- --tact elements 3 3 bya spring 3! having one end connected? to the loop H of each arm and havingjthenther end attached to a plate 32 movably amounted. in .thehousing for simultaneously adjusting the tension of the springs. A screw member 34: is passed through one wall of the switchrhousing andthreaded through the plate :32 zforneffectingadjustment thereof, which screw zmemberihas a slotted head 35 at the exterior of thehousing for operating the same.

The arms l2, during normal operation oi'the pmachina-are held in a position by the yarn passing through the eye z'i to maintain the portion 2i) of the-arms out of engagement with the contactelements 3! but upon breakage of the yarn are moved by the spring 3| thereof into circuit closing position, as hereinbefore described.

:Inorder to prevent the arms 12 frornimoving into circuit closing position in the event the yarn .becomes slack due-to; a condition occurring duringtnormal operation of the machine, thegravity operablemeansl5 arearranged to compensate for 1 such slack. --the-gravity'operable means i5 constitutes a'lever To accomplish the foregoing,

pivotally mounted between its ends at lu on an upwardly projecting ear or lug 4| on an extension 33 of the bracket. The pivot iil is off-set fromtthe middle of thelever to provide the lever with a short arm A2 and a long arm 44. The

shortarm has a yarn guide eye 55 at the end thereof positioned adjacent the eye 27 of the arm, andthe long .arn'iM has yarn guide means at the end thereof in the. form of a. laterally extending rod or fingerdfi positioned adjacent the eye Mon the base or bracket, the eye 45 and the rod .46 beingpositioned.betweenthe eyes it and 21.

The-yarn Y is threaded through the eye M,.un-

4 der the rod 46, through the eyes 45 and 21 (Fig. 2) and is then led to the knitting machine, whereby during normal operation, due to yarn demand, the portion 2'5 of the arm is held down by the tension of the yarn. Under these conditions, the short arm 42 is held down with the eye 65 substantially in registry with the eye 21 and the long arm 44 is held up with the rod 46 above the center of the eye Hi.

In theevent the yarn between the machine and the eye 21 becomes slack momentarily because yarn demand ceases for a particular strand in the normal and intended operation of the machine, the longer and heavier arm 44 with the rod it drops by gravity, so that the rod 46 presses the yarn Y against a stop element 47, shown as inclinedand extending rearwardly from extension it; while the shorter arm 52 raises to place the yarn in a zig-zag path, thereby taking up the slack. When the arms 52 and M are so positioned, the eyelid .is out of line with the eye 21 and the, rod dB .is. out of line with thexeye M. to snub the yarn and to apply a tension thereto between the rod l5 and the machine which is effective to hold the arm 12 out of circuit closing position in opposition to the influence of the spring 3 l.

The foregoing slack take-up function is accomplished without impairing the effectiveness of the device from detecting a break in the yarn and effecting stoppage of the machine. Should a break occur, the yarn goes completely slack and the lever i5 is uneffective to accommodate such slack, whereby the spring. 3i moves the arm portion 20 into engagement with the switch contact element 35.

From the foregoing description, it will be seen that the present invention provides a new and useful stop motion device for knitting machines, which has the advantages of being simpleand economical in construction, reliable in operation, and is readily adjusted. The device is readily adapted to withstand long and continuous use .nection with machines utilizing more than one color of yarn or thread. For example, when one colored thread, such as red, is being drawn by the knitting mechanism through the device from the bobbin, the other colored thread, such as blue, is stationary under a certain amount of tension brought about by the brake mechanism of this invention, which brake mechanism constituted by the rod 36 and stop element 4'? prevents the blue thread from slackening further through additional thread from the bobbin and thus prevents the arm Iii (for the blue yarn) from stopping the machine.

As various changes may be made in the form, construction and arrangement of the parts herein, without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matters herein'are to be interpreted as illustrative andnot in any limiting sense.

What is claimed:

1. In a stop motion mechanism for knitting .iachines and the like, the combination of a base, yarn guide means on said base, a member responsive to tension in the yarn adapted to effect operation of the stop motion mechanism upon breakage of the yarn, said member having one end mounted on said'base and having yarn guide means at its other end, and a member 'pivotally mounted on said base having yarn guide means at one end adjacent said yarn guide on said base and having yarn guide means at its other end adjacent said yarn guide means on said first mentioned member.

2. In a stop motion mechanism for knitting machines and the like, the combination of a base, a yarn guide eye on said base, a member responsive to tension in the yarn adapted to eiiect operation of the stop motion mechanism upon breakage of the yarn, said member being mounted on said base having a free end provided with a yarn guide eye spaced from said first eye, and a lever pivotally mounted between its ends on said base between said aforementioned guide eyes, said lever having an arm provided with a yarn guide rod adjacent said eye on said base and having a second arm provided with a yarn guide eye adjacent said eye on said member.

3. In a stop motion mechanism for knitting machines and the like, the combination of a base, a yarn guide eye on said base, a member responsive to tension in the yarn adapted to efl'ect operation of the stop motion mechanism upon breakage of the yarn, said member being mounted on said base having a free end provided with a yarn guide eye spaced from said first eye, and a lever pivotally mounted between its ends on said base between said aforementioned guide eyes, said lever having an arm provided with a yarn guide rod adjacent said eye on said base and having a second arm provided with a yarn guide eye adjacent said eye on said member, said first arm being longer than said second arm.

4. In a stop motion mechanism for knitting machines and the like, the combination of a base, switch means on said base having a contact element, a member responsive to tension in the yarn pivotally mounted on said base having yarn guide means at one end thereof and having its other end positioned to engage said element upon breakage of the yarn, yarn guide means on said base, and a second pivotally mounted member on said base having yarn guide means adjacent said guide means on said base and having yarn guide means adjacent said guide means on said first member.

5. In a stop motion mechanism for knitting machines and the like, the combination of a base, switch means on said base having a contact element, a member responsive to tension in the yarn pivotally mounted on said base having a yarn guide eye at one end thereof and having its other end positioned to engage said element upon breakage of the yarn, a yarn guide eye on said base spaced from said eye on said member, and a, lever pivotally mounted between its ends on said base between said aforementioned guide eyes, said lever having an arm provided with a yarn guide rod adjacent said eye on said base and having a second arm provided 7 with a yarn guide eye adjacent said eye on said member.

6. In a stop motion mechanism for knitting machines and the like, the combination of a base, switch means on said base having a pair of contact elements electrically connected to one terminal of said switch means, a pair of members each responsive to tension in a strand of yarn each pivotally mounted on said base and each having yarn guide means at one end thereof and each having its other end positioned to contact one of said contact elements upon breakage of its strand of yarn, said members being electrically connected to the other terminal of said switch means, whereby said switch means is adapted to close an electrical circuit upon breakage of either said strands of yarn, and stack take-up means for each strand of yarn for preventing unintentional closing of the circuit.

7. In a stop motion mechanism for knitting machines and the like, the combination of a base, switch means on said base having a pair of electrical contact elements, a pair of members each responsive to tension in a strand of yarn pivotally mounted in side by side relation on said base and each having yarn guide means at one end thereof and each having its other end positioned to contact one of said contact elements upon breakage of its strand of yarn, a spring for each of said members having one end connected to urge said last mentioned end of said members toward its contact element, a member having the other end of said springs connected thereto and a screw interconnecting said last mentioned member and said base for adjusting the tension of said springs.

8. In a stop motion mechanism for knitting machines and the like, the combination of a base, yarn guide means on said base, a member mounted on said base responsive to tension in the yarn adapted to effect operation of the stop motion mechanism upon breakage of the yarn, said member having yarn guide means at one end thereof, and gravity operable means having yarn engaging means adjacent said guide means for preventing slack in the yarn between said yarn guide means, said gravity operable means including a lever pivotally mounted on said base with a lateral finger thereon serving to engage the yarn against the base and arrest further movement of the yarn.

JACOB WACHSMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

